Adventures in Oceanography and Teaching

Ice cubes melting at the bottom of the beakers

For those of you who haven’t heard about the “melting ice cube” obsession of mine, please check out the links to other posts at the end of this post. For everybody else’s sake, let’s dive right in!

When Kristin and I ran the workshop at EMSEA14, a couple of people asked very interesting questions. One that I totally had to follow up on was this: What would happen if the ice cubes were forced to the bottom of the beakers? Of course we knew what theory said about this, but who cares? I still had to try.

If you have ever tried holding down ice cubes with straws…

…and we have a movie of this! :-)

…you might know that that is quite difficult. So this is the experimental setup I ended up with:

Ice cubes melting at the bottom of a fresh water and a salt water beaker

Zooming out a little bit, this is my fancy equipment:

The camera gets a white skirt over the tripod because the reflection of the tripod is seriously annoying

Zooming out a little more, this is the whole setup:

Chair on table in my winter garden, holding the white-ish oilcloth that serves as background. I should invest in a proper rod for the upper edge of the oil cloth, the current one has suffered a bit…

I know that some people want to try the experiment for themselves, so I’ll hide the rest of the experiment behind the cut, at least until Kristin tells me that she’s done it :-)

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So here we go: This is what happens. After less than two minutes, the ice cubes had shrunk enough that the tea thingies closed completely.

Ice cubes melting at the bottom of fresh and salt water beakers

In the picture above you can already see what is about to happen, it becomes clearer over time:

Ice cubes melting at the bottom of fresh and salt water beakers

Nice one, ey? Although I seem to have dyed my ice cubes not as well as for the last couple of experiments. You live and learn…

There are a couple of problems with this setup. For example that the ice cubes are not at the very bottom of the beakers because of the weird shape of the tea thingies. All of that can be modified, of course, and I guess at some point it will. Until then tell me: Have you tried this experiment? And how did it go???